Assessment of Ballast Layer Under Multiple Field Conditions in China

Abstract

Traditional ballast layer inspection method and maintenance standards cannot meet the current railway rapid development, such as higher speed and heavier axle load. To enhance the ballast layer inspection accuracy and supplement the maintenance standards, the ground penetrating radar (GPR) has been studied to reflect ballast layer fouling level in this paper, including indicator (from GPR signal processing) investigation, fouling composition and correlation between GPR signal and fouling level (assessed by sieving). The railway lines under different complex conditions, including ballast material, gross passing load, clean and renewal year as well as transportation type are considered as factors influencing the ballast layer fouling level. The results show that the GPR is able to assess ballast layer fouling level with only 1-7% difference to the assessment (through sieving results). In addition, the fouling composition (ballast material) has great influence on the GPR signal, especially the metal material, such as the iron ore. Future development direction on GPR should be towards more precise analysis on both the fouling level and the fouling composition identification.

Keywords: Ground Penetrating Radar, GPR, railway ballast, track inspection, ballast fouling, track geometry